On many ships the emergency towing arrangements required by SOLAS may also be suitable for escort/pull-back requirements provided that such use does not in any way compromise the deployment and use of the emergency towing arrangements for their SOLAS purpose. For new installations it is recommended that consideration is given to designing the emergency towing arrangement to provide this dual purpose capability. The following recommendations apply where separate strongpoints and chocks are provided specifically for tug escort and pull-back duties. In such cases:
The major components and supporting structure should be designed for a load that is a minimum of ••2 times the SWL rating
towing arrangements should be adequate for towing line angles up to 90° from the ship’s centreline ••to both starboard and port in the horizontal plane and to 30° below horizontal in the vertical plane
the fairlead (chock) should be located on the stern as close as possible to the centreline of the ship. ••(If the emergency towing arrangement is used, the strong point should be located so as to facilitate towing from either side of the stern and to minimise the stress on the towing system - see Resolution MSC.35(63))
the fairlead (chock) opening should be oval or to have well-rounded corners••
the towing or connection point should be aligned longitudinally with the fairlead (chock) and clear ••of all obstructions
the fairlead (chock) should have a minimum diameter of 600 mm and a minimum height of 300 mm••
the minimum distance from strong point to fairlead (chock) should be 4.0 metres. It is recognised ••that this may be difficult to achieve on ships of less than 50,000 DWT, but it is aimed at ensuring that the eye splice of the towing line sits inboard of the fairlead (chock). If the distance from strong point to fairlead (chock) is less than 4.0 metres, the tug should be advised. (This recommendation does not apply if the emergency towing arrangement is used as, in that case, the chafing gear will lie in the chock)
each fitting should be clearly marked by bead weld outline with its SWL. The SWL should be ••expressed in tonnes (letter ‘t’) to avoid any confusion
fixed gear such as strong points, fairleads (chocks), foundations and associated supporting structure ••should be demonstrated as adequate for the loads imposed. The ship should hold a copy of the manufacturer’s type test certificate for the fittings or a certificate confirming that the fittings are constructed in strict compliance with a recognised standard that specifies design load, safety factor and load application. The ship should also hold a certificate attesting to the strength of the strong